The decision does not exclude the possibility of Pte Manning being ultimately acquitted of the charge.

No 'evil intent'

The accused, who appeared to be following the proceedings closely, showed no reaction to the ruling.

He has previously pleaded guilty to 10 of the more than 20 charges he faces.

At the scene

By Rajini VaidyanathanBBC News

Today's ruling from the judge on the charge of "aiding the enemy" was highly anticipated. Outside the court at Fort Meade, Pte Manning's supporters said the case could deter other "whistleblowers" from sharing classified information which might be in the public interest. One of them asked whether, if someone leaked something to a newspaper, they too could be seen as "aiding the enemy".

If found guilty on this count, Pte Manning faces life in prison. For him to be convicted, it needs to be proved that he gave potentially damaging information to an enemy, knowingly, and with evil intent. It is this last clause that could be the trickiest to ascertain. Prosecutors argue they have proof al-Qaeda accessed information from Wikileaks, and that by posting the information Pte Manning would have known terror groups could see it.

But on Thursday, Judge Lind also denied a defence request to drop a computer fraud charge.

She is still considering a motion by Pte Manning's lawyers to dismiss five charges of theft.

Some two dozen of his supporters sat quietly in the courtroom, some wearing t-shirts printed with the word "truth".